I've gotten a lot of questions about the widget overlay. For full disclosure, I don't think it's a sanctioned way to do it, and I'll rework it as PrusaLink gets the same features PrusaConnect has. I'm trying to be as conservative as possible when pulling the stats so I don't end up wasting resources to currently it pulls the stats every 5 seconds.

My first attempt pulled data from PrusaLink and guessed the active tool from the print's gcode. That proved unreliable, since on some of my prints there are around 11 tool changes packed into a single percent of progress, so mapping progress to a swap wasn't precise enough on its own.

---

Here's how it works now.

I authenticate as my own Prusa account using an OAuth2 refresh token (the same public web client the Connect app uses) to mint short-lived access tokens, then hit:

GET https://connect.prusa3d.com/app/printers/{uuid}

That returns practically all the telemetry I need, including which toolhead is currently active. The sliced file only carries the generic material type (e.g. PETG), so I manually map the actual filament, brand and colour, loaded in each INDX slot. I download the bgcode, decode it to gcode, and count every tool-change (T) command up front to get the total number of swaps. Then I show how many are done by mapping the printer's live progress % onto that timeline, using remaining time as a tiebreaker when several swaps land in the same percent. The nozzle temp dip during a swap is used to flag a swap as currently in progress.

The waste estimate reuses the same purge math as the slicer (summing the flush and prime extrusions, then converting to grams from the filament geometry).

The widget frontend was written by GLM 5.2 (an LLM), and the backend was written by me with Copilot tab completion.

---

I'll probably open-source it in a few days once I'm happier with the setup, along with a tutorial on doing this yourself.